1. Field of the Invention
The invention relates to a method of manufacturing a solar cell.
2. Description of the Related Art
Solar cells are devices, which convert light energy into electrical energy by the photovoltaic effect. Today, there is a high demand for solar cells because they have many applications. For example, solar cells are used for powering small devices like calculators. Further, an increasing demand in solar cells is due to their usage in vehicles and satellites. Solar cells even have the potential of substituting state of the art power plants as solar cell technology is a technology branch favored by society now. The reason for this favoring can be found in the fact that electricity produced by solar cells is renewable ‘clean’ electricity.
Solar cells include a semi-conducting material, which is used to absorb photons and generate electrons via the photovoltaic effect. A semi-conducting material typically used for manufacturing solar cells is silicon. In solar cells, silicon can be used either as mono- or polycrystalline silicon.
In order to make the silicon solar cell technology more competitive to other state of the art technologies, which also provide electrical energy, the effectiveness in solar cell production has to be continuously increased. This includes, for example in the case of silicon solar cells, a reduction of the thickness of the silicon material used for manufacturing of the solar cells. Reduction of the thickness reduces the silicon consumption and thus reduces the material cost, which is an important aspect because the silicon price is increasing continuously due to the limited amount of available silicon.
However, when decreasing the thickness of the silicon layers in a silicon solar cell, for example, recombination at the rear surface of the solar cell occurs. Recombination reduces the open circuit voltage and also the short circuit current density. One way to circumvent this is by using dual emitter solar cells. However, manufacturing dual emitter solar cells based on silicon is not standard due to high manufacturing and, therefore, production costs. Typically processes now involve lithography and sputter technologies, which are very expensive to use and maintain.
Therefore, there is a need to provide an improved method of manufacturing solar cells, wherein the production costs are reduced.